1. Field of the Invention
The present invention relates to a light transmittance adjusting apparatus to be installed on a rear window, a side window or a sunvisor of automobiles or buildings such as stores or the like.
2. Description of Related Art
In recent years, there is a tendency for decreasing the light transmittance of the rear window of automobiles or windows of buildings to reduce the rate of the power consumption of air-conditioners in summer in particular. There are also cases in which characters, diagrams, patterns or marks are printed on the windowpanes or transparent films.
According to the light transmittance adjusting apparatus disclosed in Laid-Open Japanese Patent Publication No. 6-8730, the light transmittance of a windowpane is adjusted by displacing a plurality of plates from each other, the plates having non-transparent or light interception sections and transparent light transmission sections formed thereon parallelly and alternately with each other in a vertical direction. According to the light transmittance adjusting apparatus disclosed in Laid-Open Japanese Utility Model Publication No. 58-25218, the light transmittance of a windowpane is adjusted by displacing a pair of transparent plates from each other, the plates having a nontransparent light interception section on which a checkered pattern is formed.
These light transmittance adjusting apparatuses have the following disadvantages: If the parallelism or the positioning accuracy of the plates having the light interception sections and transparent light transmission sections formed thereon vertically is low, a gap is formed between the light interception sections horizontally opposed to each other in a light interception state, thus preventing the light transmittance from being reduced to a desired degree; or vertical ends of the light interception sections horizontally opposed to each other overlap with each other, thus forming a dense stripe in the light interception sections.
The light transmittance adjusting apparatus disclosed in Laid-Open Japanese Patent Publication No. 6-59201 has a complicated construction because it comprises an electrostatic actuator provided with a movable member and a fixed member and a pair of polarizing plates.